A DDoS attack stands for Distributed Denial of Service attack.
It is a cyberattack where an attacker uses many computers, servers, or internet-connected devices (often a “botnet” of compromised devices) to overwhelm a target system with traffic or requests, making it slow or completely unavailable to legitimate users.
How it works
Imagine a restaurant with 50 seats:
- Normally, customers arrive at a manageable rate and get served.
- During a DDoS attack, thousands of fake customers flood the restaurant at once.
- Real customers can’t get a seat or receive service.
The same thing happens to websites, online games, APIs, or networks.
Common types of DDoS attacks
- Volume-based attacks
- Flood the target with massive amounts of traffic.
- Example: sending millions of requests per second.
- Protocol attacks
- Exploit weaknesses in network protocols.
- Example: SYN flood attacks.
- Application-layer attacks
- Target specific services such as web pages or login systems.
- Example: overwhelming a website’s search function with requests.
Effects of a DDoS attack
- Website outages
- Slow performance
- Service interruptions
- Lost revenue
- Increased infrastructure costs
Why “Distributed”?
A regular DoS (Denial of Service) attack comes from a single source.
A DDoS attack comes from many sources simultaneously, often thousands or millions of devices spread across different locations, making it much harder to block.
How organizations defend against DDoS attacks
- Traffic filtering and rate limiting
- Content Delivery Networks (CDNs) such as Cloudflare
- DDoS protection services from providers like AWS Shield and Google Cloud Armor
- Load balancing
- Web Application Firewalls (WAFs)
Simple example
If a website normally receives 10,000 visitors per hour, a DDoS attack might generate millions of fake requests per hour, consuming all available bandwidth and server resources so real users cannot access the site.
DDoS attacks are illegal in most countries and are often used for extortion, vandalism, political disruption, or as a distraction while other cyberattacks are carried out.
